Warning: Missing argument 3 for write(), called in /www/wwwroot/biwei1.cn/incs/robot.php on line 68 and defined in /www/wwwroot/biwei1.cn/incs/data.php on line 487 Fourier transforms are a tool used in a whole bunch of different things. Jez Swanson explains what a Fourier transform does, its relationship with epicycles and some different ways it can be useful [read more: ]